When a vehicle moves around a curve, it becomes subject to a possibility of skidding or overturning, depending on a variety of conditions, such as, first of all the speed of the vehicle, which is the main and only parameter that can be changed by the driver of the vehicle if he gets a timely warning that this parameter tends to exceed safe limits. As known from physics, the centrifugal force, which is the cause for the development of an overturning moment, is dependent on the square of the speed of the vehicle. It is also dependent on the radius of curvature, the slope of the road surface and the combination of road and weather conditions.
The possibility that a vehicle moves in a succession of right and left turns, which leads to alternative compression and decompression of the shock absorbers of the vehicle's suspension system further enhances possibilities of overturning, but also of the driver loosing control of the vehicle.
Prior art approaches to alleviation of the problem of monitoring an impeding overturning condition when the vehicle moves around a curve generally related to sensor means which, when an alarm condition was monitored, activated automatic operations, such as effecting reduction of available power or even shutting off the motor of the vehicle without any action being taken by the driver. An example of such a device is described by Lengd. Agric. Inst. in SU-816849.
The above approach is however considered inappropriate for experienced drivers, who dislike leaving control of their car to automatically activated systems. Moreover such automatically activated systems are highly complicated and costly.
The alternative prior art approaches relate to devices that aim at providing a warning to the driver of the vehicle, so that he may take remedial measures. Such devices as by way of example disclosed by Anton Ellinghaus in DE-4342732 or by J. A. Sanner in U.S. Pat. No. 4,952,908 relate to tractor-trailer vehicles, wherein the device is split in two parts, one sensing means mounted on the trailer and coupled to alarm means mounted on the tractor. The above sensing means in U.S. Pat. No. 4,952,908 is proposed to include a pair of angular mounted normally open mercury switches arranged to detect lateral forces to the right or left to a degree conducive to roll-over. The device proposed by Johns et al in U.S. Pat. No. 3,778,763 is also split in two parts, wherein one part is the sensing means and the other part the means for emitting a visual or audible alarm, positioned in the drive compartment of the vehicle. The sensing means in Johns et al also employs a mercury switch sensing device, having a U shaped mercury structure, which senses tilting movements of the vehicle.
Whilst the above devices are aimed to activating the driver in taking remedial measures, so as to return the vehicle in safe course, they are powered by the battery of the vehicle and they become unreliable due to their split configuration and therefore the need of transferring the signal from the sensing means to the means for emitting a visual and/or audible alarm.
Furthermore, none of the devices of the prior art, which operate so as to provide a warning to the driver of the vehicle and leave to him taking the remedial measures, includes appropriate means for calibration of the sensing device, so that a single make of the device may be adjusted into the combination of performance characteristics of different motor cars and into the particular driving habits and skills of individual drivers. It therefore follows that due to varying vehicle performance characteristics and driving habits of individual drivers, devices of the prior art may fail in producing a timely warning, appropriate to the above mentioned changing conditions.
Devices of the prior art also fail to provide means for adjusting the operation thereof to changing operating conditions, and in particular to changing road conditions as such conditions arise in the variation between dry and wet road surface.
The object of the present invention is to effectively overcome the abovementioned shortcomings of the prior art by providing a device for warning drivers of automobiles of excessive speed of turning around a curve, so that they may be alerted in taking remedial measures, wherein the device is characterized by being autonomous, compact and self powered, achieving low cost and trouble free reliable operation, wherein sensing of excessive speed in right or left turns is being monitored by a first pair of oppositely inclined mercury switches.
Another object of the invention is to propose the device with means for adjusting the operation thereof to changing operating conditions in dry or wet road surface, this means being an additional, accordingly calibrated second pair of oppositely inclined mercury switches, wherein in use the device may be alternatively set to operate with either the above mentioned first or second pair of oppositely inclined mercury switches, so as to appropriately adjust to operation in dry or wet road surface.
Another object of the invention is to propose a device with varying response sensitivity and calibrating means of the sensing device, so that it may be adjusted into the combination of varying performance characteristics of different motor cars and into the varying particular driving habits and skills of individual drivers.
Still a further object of the invention is to provide for the device to be alternatively mounted onto the driving panel or embodied into a suitable location thereof or mounted onto the windscreen, wherein the device is advantageously provided with a housing divided in portions, so that it may be fixedly mounted, whilst assuming the desired horizontal orientation.